A dental crown, often called a cap, is a custom restoration placed over a damaged tooth. Its function is to restore the tooth’s shape, size, and strength, allowing for normal function like biting and chewing. While the crown provides a durable barrier, the underlying natural tooth structure and its internal pulp remain susceptible to bacterial invasion and infection. Bacteria can still find a path to the sensitive tissues inside the tooth despite the outer protection.
How Infection Develops Beneath a Crown
Bacteria can bypass the crown’s defense through a few pathways. One common route is margin leakage, occurring where the crown edge meets the natural tooth structure near the gumline. If the crown is not perfectly sealed or hygiene is poor, plaque accumulates, leading to recurrent decay that tunnels inward beneath the restoration and causes infection. Another entry point is physical damage, such as a crack or fracture, which compromises the seal and allows bacteria to infiltrate. Problems also arise if the tooth was not root-canaled before crown placement, or if a previously treated root canal fails, allowing bacteria to multiply and cause a periapical infection to develop at the root tip.
Identifying the Symptoms
The presence of a bacterial infection beneath a crown often presents with noticeable signs requiring professional evaluation. Persistent or severe pain is a common indicator, especially a throbbing sensation or discomfort that intensifies when pressure is applied, such as when biting or chewing. This pain results from inflammatory pressure building up inside the tooth’s pulp chamber or surrounding bone.
Heightened sensitivity to temperature changes is a frequent symptom, particularly when the discomfort lingers after the stimulus is removed. Localized swelling and tenderness in the gum tissue surrounding the crowned tooth signal the body’s inflammatory response. In advanced cases, an abscess may form, appearing as a small, pimple-like bump on the gum that may release a foul-smelling discharge. A persistent bad taste or odor, not resolved by brushing, can also indicate the drainage of pus from this underlying infection.
Professional Treatment Paths
Treatment for an infected crowned tooth focuses on eliminating bacteria, alleviating discomfort, and saving the tooth structure. One common procedure is root canal retreatment, performed by making an access opening through the existing crown. This allows the dentist to reach the pulp chamber, remove infected tissue, clean the root canals, and then seal them. If the crown is sound, the access hole is filled; otherwise, the crown may need replacement to restore the seal.
If the issue is extensive decay at the margin or a poorly fitting restoration, the dentist may need to remove the existing crown entirely. Once removed, the full extent of the decay on the remaining tooth structure is assessed and removed. After the decay is cleaned and any necessary subsequent treatment is performed, a precise new crown is fabricated and cemented to ensure a proper, bacteria-resistant seal.
Extraction is the final recourse, reserved for situations where the infection has caused irreparable damage, such as significant bone loss or a non-restorable fracture. Removing the tooth eliminates the source of the infection and prevents its spread. Following extraction, patients discuss options for replacement, such as a dental implant or a fixed bridge, to restore function and maintain alignment.